As I'm not learning how to count beans I don't know about the insurance costs of FBW planes as opposed to planes with "conventional" controls, but ofcourse since Airbus has been using FBW since 1985 ( I think) and Boeing has already developed it for the 777, the development costs are much much higher if you have to start from scratch like Fokker might as well do and Embraer has done recently.
The Embraer 170 and 190 are the first Brazilian planes to have FBW, yet they, like the 777 use a yoke. Ofcourse one following the Embraer tradition of having this Concorde/Trident/Tu-204 bicycle-type yoke. I have yet to fly a plane/simulator with this kind of yoke, but like more things British, it somehow makes sense although being a bit strange.
Concerning mechanical backup: Airbus uses a system that allows the rudder and trim wheels to be used for directional control if all computers fail for whatever reason, even in the event of a complete electrical power failure. Provided the plane is still hydraulically powered of course by the demand pumps on the engines or even just the RAT on the green system.
JJ/TT2: mechanical linkages between sticks/yokes make no sense whatsoever in a FBW aircraft. In buses, they put a sidestick priority button on the glareshield the PF must push to "get" manual control of the plane.
